Hi,
I need an email validation function in asp.net.
I can use custom validation but there is a problem.
I have a textbx that user enters email separated with commas and I don't know how to validate each email
that is the asp code
strTo=request.form("to")
strEmails=split(strTo,",")
For each strTo in strEmails
if IsEmail(strTo)="True" then
%>
<table class=Err align=center>
    <tr>
    <td class=font1><%response.write email & " " & "<b>" & strTo & "</b>" & emailNotValid%></td>
    </tr>
</table>
<br>
<%
response.end
end if
next

Couldn't you put the email addresses into an array and check them separately?

Dim EmailAddresses As Array = Split(Request("EmailAddresses"), ",")
For i = 0 to Ubound(EmailAddresses)
If not CheckEmailFunction(EmailAddresses(i)) Then
Response.Write(EmailAddresses(i) & "<br />")
Next

ok.thanks rstelma
now can you give me asp.net email function
I USED before the asp version:
Private Function IsEmail(byVal mailaddress)
    Dim tmp, x, y, bErr, tmp2, objReg
    Dim objMatch, z, i
    bErr = False
    tmp = Trim( mailaddress )
    tmp = CStr( mailaddress )
    if len(tmp) < 6 then
        IsEmail = "True"
        Exit Function
    end if
    If instr(tmp, "@") then
        x = instr(tmp, "@")
        y = instr(x + 1, tmp, "@")
        'On Error Resume Next
        y = CLng(y)
        If Err Then bErr = True Else bErr = False
        On Error GoTo 0
        If bErr Then
            IsEmail = "True"
            Exit Function
        End If
        if y <> 0 then
            IsEmail = "True"
            Exit Function
        end if
    Else
        IsEmail = "True"
        Exit Function
    End If
    If InStr( Left( tmp, CLng(x) ), "." ) Then
        IsEmail = "gg"
        Exit Function
    Else
        tmp2 = Right( tmp, Len(tmp) - CLng(x) )
        If InStr( tmp2, "." ) Then
            Set objReg = New RegExp
            With objReg
                .Global = True
                .IgnoreCase = True
                .Pattern = "[A-Z]|[0-9]"
                Set objMatch = .Execute(tmp2)
            End With
            If objMatch.Count = 0 then
                IsEmail = "True"
                Exit Function
            End If
            Set objMatch = Nothing
            Set objReg = Nothing
        Else
            IsEmail = "True"
            Exit Function
        End If
    End If
    z = InStr( tmp, "." )
    tmp2 = Right( tmp, Len(tmp) - z )
    Set objReg = New RegExp
    With objReg
        .Global = True
        .IgnoreCase = True
        .Pattern = "[A-Z][A-Z]"
        Set objMatch = .Execute(tmp2)
    End With
    If objMatch.Count = 0 then
        IsEmail = "True"
        Exit Function
    End If
    Set objMatch = Nothing
    Set objReg = Nothing
    For i = 1 to Len(tmp)
        tmp2 = Mid( tmp, i, 1 )
        Select Case tmp2
            Case "(", ")", ";", ":", ",", "/", "'", chr(34), _
                 "~", "`", "!", "#", "$", "%", "^", "&", "*", _
                 "+", "=", "[", "]", "{", "}", "|", "\", "?", _
                 " ", "<", ">"
                IsEmail = "True"
                Exit Function
            Case Else
        End Select
    Next
    IsEmail = ""
End Function

Here ya go.

    Function CheckEmail(ByVal Value As String) As Boolean
        Dim ex As Regex = New Regex("^[a-zA-Z][\w\.-]*[a-zA-Z0-9]@[a-zA-Z0-9][\w\.-]*[a-zA-Z0-9]\.[a-zA-Z][a-zA-Z\.]*[a-zA-Z]$")
        Return ex.Match(Value).Success
    End Function